Method of preparing composite poppet valves



Feb 1o, 194s. J. WISQHHQSEN 2,435,948

lm'mon or' PREPARING courosITE PoPPET VALVES Filed sept. a, 19441yPatented Feb. 10, 1948 METHOD OF PREPARING COMPOSITE POPPET VALVES J ohnWischhuscn,

Euclid, Ohio,

assigner to Thompson Products, Inc., Cleveland, Chio, a

corporation of Ohio Application September 8, 1944, Serial No. 553,158

Thisinvention relates to the preparation of poppet valves havingcomposite head dome and seat portions composed of forgeablestress-resistant metal clad with corrosion-resistant metal.

Specifically the invention deals with the simultaneous welding togetherof a metal billet of tough, stress-resistant forgeable steel, a ring ofcorrosion-resistant metal to form a seating face for a valve and a diskof corrosion-resistant metal to form a cover for the head of the valvewhereby heretofore-necessarypuddling operations for forming the valvetseat face are eliminated.

Composite metal poppet valves having corrosion-resistant valve headcovers and corrosionresistant seating faces have heretofore only beenmade by puddling operations which weld molten, corrosion-resistant alloyto the valve body member and, in some instances, to thecorrosionresistant valve head cover. These puddling operations, however,deleteriously aiect the metal and great care must be taken to avoidburning. Even when the puddling operation is carefully performed, thehigh temperatures necessary to melt the corrosion-resistant metal causegrain changes to occur in the valve body metal. These grain changesdeleteriously affect the strength of the valve.

In accordance with this invention, a billet or slug of tough,stress-resistant valve body metal is formed with` a reduced-diameter endportion providing a flat shoulder inwardly from one end thereof. Thisreduced-diameter` portion has a ring of corrosion-resistantmetal'tightly fitted thereon by press or shrink-fitting operations, withthe ring bottomed on the shoulder. The reduceddiameter portion of thebillet and the ring are finished to a flat uniform dimension and arecovered with a disk of corrosion-resistant metal. The billet, ring, anddisk are then simultaneously subjected to a pressure welding operationfor production of a composite blank. The ring is simultaneously weldedto both the billet and the disk, while the disk is also welded to thebillet. The ring provides metal along the side of the composite blankfor the seating face of a valve to be made from the blank. The diskprovides metal for forming the cover on the head of the valve to be madefrom the blank.

The invention eliminates the heretofore-necessary puddling operation forforming valve seating faces of highly corrosion-resistant metal onpoppet valves.

It is, then, an object of this invention to provide a method ofmanufacturing composite pop- 4 Claims. (Cl. 229-1563) pet valves withcorrosion-resistant seating faces without the necessity for puddling thecorrosionresistant metal onto the valve body.

A still further object of the invention is to form pOpDet valves withcorrosion-resistant metal-clad head and seating faces simultaneouslysecured to a billet of valve body metal.

Another object of the invention is to form, by a pressure weldingoperation, a poppet valve having la corrosion-resistant seating faceformed from a separate ring o: metal.

Another object of the invention is to form aircraft engine exhaustvalves having head and seating face portions clad withcorrosion-resistant metal in integral bonded relation to the valve bodymetal without involving a fusingof either the body metal or the claddingmetal except along the weld line therebetween.

A still further object of this invention is to provide a method oi'making composite poppet valves by welding a ring and a separate claddingdisk of the same metal as the ring onto a billet to avoid formation ofvoids `such as would occur if the ring and cladding disk were in onepiece.

Other and further objects of the invention will be apparent to thoseskilled in the art from the following 'detailed description of theannexed sheet of drawings which, by way oi' preferred example,illustrate one embodiment of the invention.

On the drawings:

Figure 1 is a vertical cross-sectional exploded view of the partsforming the composite blank for the process of this invention.

Figure 2 is a vertical cross-sectional view of the composite blankmounted in a pressure welding device for ,pressure welding of the parts.

Figure 3 is a vertical cross-sectional view of the composite blankformed from the pressurewelding operation of Figure 2.

Figure 4 is a vertical cross-sectional view of a blank formed from theblank of Figure 3 by extruding.

Figure 5 is a cross-sectional view of a blank formed from the blank ofFigure 4 by piercing, machining and cutting operations.

Figure 6 is a vertical cross-sectional view of a finished hollow poppetvalve having thehead portion, thereof clad with corrosion-resistantmetal and having a. corrosion-resisting metal seating face.

As shown on the drawings:

In Figure 1, the reference numeral l0 designates generally a cylindricalsolid metal billet or slug composed of forgeable stress-resistant Percent Nickel 14 Chromium 14 Tungsten 2.4 CarbonV 0.45 Molybdenum 0.35Remainder substantially all iron.

The billet I0 has a reduced diameter pilot 'portion Ilia at one endthereof bounded ,by a cylindrical side wall IIib of a diameter less thanthe diameter of the billet. A flat shoulder I0c is thus provided on thebillet around the base of the pilot portion Ilia. The pilot portion Illahas a fiat top I 0d.

A ring Il of rectangular cross section is provided for yieldingcorrosion-resistant metal to produce the valve seat face or seating ringaccording to this invention. A solid flat disk I2 also composed ofcorrosion-resistant metal is provided for forming the cladding or coverfor the valve head according to this invention.

The ring II and disk l2 are composed of corrosion-resistant metals,examples of which are: nickel, chromium, and iron alloys; nickel,molybdenum and iron alloys; non-ferrous nickel-chromium alloys;chromium-tungsten alloys, and the like.

The ring II has a flat cylindrical inside wall IIa concentric with butoi' a diameter somewhat less than the diameter of the wall IIlb of thepilot portion Illa, so that the ring only fits around the pilot portionwith a shrink or press nt. The ring I I also has a fiat bottom face IIbfor fitting on the shoulder I0c of the billet I0 together with a flattop face lic adapted to be seated flush on the top face IIid of thepilot portion Illa when the bottom face II b is bottomed on the shoulderI0c. yTo insure complete mating of the bottom face IIb and shoulder I0cthese surfaces can be given a grind finish.

The disk I2 has a fiat bottom face I2a. In order to insure completemating`contact between the bottom face |2a of the disk, I2 and the topfaces IIc and IIid of the ring and billet throughout the entire matingareas of these members, it may be desirable to grind and polish the endfaces IIld and IIc after the ring has been tightly fitted onto the pilotportion Illa by a press fitting or a shrink fitting operation. The faceI2a should have a similar ground and polished finish.

As shown in Figure 2, the composite assembly of billet I0, ring II anddisk I2 is placed in a high pressure welding apparatus I2 on the pressplaten Il thereof. The platen I4 is moved toward a fixed platen I5 bymeans of a pressure-actuated ram I6. A mica disk I1 is interposedbetween the platen I5 and the disk I2 to prevent the disk I2 fromsticking to the platen I5 during the welding operation.

'I'he ram I6 exerts pressures of from 4,000 to 6,000 lbs. per squareinch of contacting surface between the bottom face I2a of the disk andthe top faces I0d and II c of the billet and ring. The specific desiredpressure will vary, depending upon the alloys used for the billet ringand disk.

A torch ring I8 embraces the composite assemmy 1n the apparatus la anddenses an annular 7l 4 passageway Ita completely enveloping theassembly. The ring I8 has a plurality of jet holes IIb at spacedintervals around its inner periphery to join the passageway Ila with theperiphery of the composite assembly. f

Acetylene and oxygen is fed to the passageway Ia o1' the ring Il and themixture of gases bleeds out through the Jet holes Ilb to form jets IlAwhich are ignited for impingingl upon the composite assembly.

'I'he ring I8 is reciprocated axially. of the composite assembly tocover an, area on both sides of the contacting surfaces of the disk withthe billet and ring and of the ring with the billet. The ring I8, forexample, may be oscillated between levels designated by the lines A andB.

In addition, the ring Il is oscillated during its up and down reciprocalmovements so that the jets I8 will not impinge upon the same spotsaround the assembly. 'I'he oscillation is usually an arc of about 15.

The jets I9 heat the assembly inwardly from the outer peripheriesthereof so that, for example, the contacting pairs of surfaces I2a andIlc; I2a and Illd; IIa and IIIb; and IIb and IIic; are heated byconduction to welding temperatures. These pairs of surfaces are sealedby the pressure apparatus due to their exact mating fits so that air,dirt, or any foreign matter is excluded and the resulting weids are freefrom slag. The welding temperatures are below the melting points of themetals and the heating time and temperatures developed will depend uponthe compositions of the metals. For disks and rings composed ofnon-ferrous nickel-chromium alloys and base metal billets composed ofvalve steels, welding temperatures of around 2300 F. are reached. l

During the heating operation, the composite assembly is continuallysubjected to the selected pressure within the 4,000 to 6,000 lb. persquare inch range by the pressure ram Il and, in about eleven minutes,three inch diameter billets and disks are usually heated to theirwelding temperatures, and the softened metals bow outwardly adjacent theweld lines to produce a blank 2l. shown in Figure 3, which is generallylcylindrical with flat end walls but with a bulge 20a in the side wallthereof adjacent one end wall. The blank 201s composed of a cap 2| withan integral shoulder 2Ia on a body portion 22 having apilot end 22asurrounded by the shoulder 2Ia.

The cap 2| is secured to the billet 22 alongv a weld line 23 having asomewhat wavy contour with a top wall having a, central convex portionmerging into concave outer peripheral portions and depending as at 23adownwardly in a bowed or curved path to a substantially fiat outwardlyextending line portion extending outwardly from g. the top portion ofthe weld line 2l.

The cap 2i, of course, is formed from the disk I2 and the shoulder 2Iaon the cap is formed from the ring Il. The body portion 22 is formedfrom the billet I 0.

In place of flame jets for heating inthe pres- I. dotted lines C-C ofFigure 3 to produce a straight cylindrical blank.

The blank 20 of Figure 2, after being ground into cylindrical shape. isheated to forging temperatures of' about 19.50 to 2050' F. and ispartially extruded to produce the headed cup-shaped .coolant 38 such assodium or the like.

blank 2l of Figure 4. The blank 2l of Figure 4 is composed of acup-shaped member 2i formed from thebillet Ill having a cylindrical sidewall 23a and an end wall 2lb receiving a cap 2l thereon with a portion21a of the cap covering the top of the end wall 2Gb and with askirt-portion 2lb .surrounding the end wall 26h and Joined with therein.'I'he piercing operation changes the.

contour of the original wavy weld line 2l tc a continuous arcuatecontour. The recess lI! is undercut to provide an enlarged head cavity32a adjacent the blind end wall Sla thereof. The end wall lla of theblank l! is covered with a cap Il having a skirt portion 33a surroundingthe upper end ofthe cup member. 'I'he cap I! is machined to form alathe-centering lug'llb at the axial center of the blank.

'The blank 30 of Figure 5 is further forged and machined to produce thefinished poppet valve Il of Figure 6. Thisvpoppet valve 3i has a bodyportion composed of the billet metal I l formed from the cup Il and acladding or cover on the head of the body portion composed of the diskand ring metal and formed from the head Il of the blank 3l.

As shown in Figure 6, the poppet valve is composed of a main body I1 anda head`ll. The main body I1 has a hollow tubular stem portion 31a with asolid tip or bottom end IIb and an outwardly flaring upper-neck end 31e.Theneck 31e is bounded by an outer peripheral upstanding portion 31dhaving a covering dome lle. The body Il thus has head and stem portionsdefining a head and stem cavity partially filled with The head and stemcavities receiving the sodium are deiined only by body metal from thebillet I0.

The cover or cladding n includes a head dome cover or cladding portion38a formed from the disk i2 and a depending skirt portion lib formedfrom the ring Il. This skirt portion surrounds the upstanding peripheralportion I'Id of the valve body and defines the valve seating face. It iswelded to the portion "a as indicated above and, of course, is welded tothe body portion.

From the above descriptions it will be understood that the inventionproduces a composite hollow poppet valve with a main body portioncomposed of tough, stress-resisting metal and having a head covered withan integrally connected skirted cover forming a corrosion-resistantcladding for the head dome and seating face of the valve. The skirt softhe cover is formed initially from a ring that is separate from thevalve dome covering portion of the cover.

The valve head cover and the valve seating face are integrally welded tothe body of the valve without melting the covering metals beyond theirsoftening points, so that molten puddling-on operations are avoided.

It will. of course, be understood that various details of constructionmay be varied through a wide range without departing from the principlesof this invention and it is, therefore, not the Purpose to limit the`patent granted hereon otherwise than necessitated by the scope oi theapi pended claims.v

I claim as my invention:

1. The method of forming a poppet valve which comprises forming acylindrical metal billet 'of tough forgeabie valve steel with areduceddiameter pilot portion on one end thereof, tightly f fittingaring of corrosion-resistant metal onto the pilot portion of the billet,covering the ring and pilot portion of the billet with a disk ofcorrosion-resistant metal, welding the billet, ring and disk together toform a composite blank having a body portion composed of billet metalcovered at one end by a sklrted cap. extruding the body portion of theblank to a reduced diameter size, terminating the extruding operationbefore the `disk Vmetal has been deformed but after the ring metal hasbeen partially extruded and deformed into the body metal to provide a lheaded blank with the ring metal. defining a. shoulder between the headand reduced-diameter body, piercing the body of the headed extrudedblank, terminating the piercing operation in the head of the blank andin advance of the weld line between the disk and body portions .of theblank to form a headed recessed cup-shaped blank, under-cutting theblind end vof the recess in .the cup-shaped blank to form an enlargedhead and cavity in the cup,. forging the undercut cup-shaped blank toform an elongated stem from the body portion thereof, and. shaping theresulting stemmed blank into poppet valve shape and size to therebyprovide a poppet valve having a main body composed of the billet metaland clad at the head end thereof with a skirted cover composed ofthedisk and ring metal.

2. The method of making a poppet valve with a corrosion-resistantmetal-clad head and seating face without puddling corrosion-resistantmetal onto a valve body which comprises forming a metal billet of valvesteel with a reduceddiameter end pilot portion, tightly fitting a ringof corrosion-resistant metal around the pilot portion of the billet,forming flush flat end faces on the pilot portion and ring, covering thering and pilot portion of the billet with a corrosionresisting diskhaving a fiat end face to place the end face of the disk in full.intimate contact with the flush fiat end faces of the pilot portion andring. welding the billet, ring and disk together to produce a compositeblank having a main body portion composed of the billet metal covered onone end by a skirted cover composed of the ring and disk metal,extruding the main body portion of the composite blank to a reduceddiameter size. terminating the extruding operation after the ringportion of the composite blank has been partially extruded to form aninclined shoulder connecting the reduced-diameter body portion with theunreduced-diameter disk portion, piercing the extruded body portion toform a hollow cup therefrom, terminating the piercing operation inadvance of the disk metal, undercutting the blind end of the pierced cupto form an enlarged cavity therein, terminating the undercuttingIoperation in advance of the ring metal, and forging the cup into anelongated hollow stem thereby producing a poppet valve-shaped memberhavinga body portion composed of the billet metal and a head portionclad with a skirted cover composed of the ring and disk metals.

3. The method of makingv composite poppet valves which comprises forminga metal blank y mesme with a reduced-diameter cylindrical end ,portionand a flat shoulder at the base of the end portion, 'tightly tting aring of corrosion-resistant metal onto the reduced-diameter portion ofthe blank m mu seating relation with the shoulder of the blank,finishing the exposed end faces of the rinz and thelreduced-diametercylindrical end portion of the blank to provide a iiush iiat end surfaceon the assembly, finishing an end face of a corrosion-resistant metaldisk to provide a ilat end surface thereon to mate with the end surfaceof the assembly, -plac- `ing the iinished end surfaces oi the disk andas` sembly together in full contacting relationv to cover the assemblywith the disk, welding the assembly together atpressures of about 4000to 6000 lbs. per square inch o! .contacting surface and at temperaturesless than the melting point of the corrosion-resistant metal to therebyprov duce a composite metal blank with a bowed side wall, removing `thebowed portion ot the side wall of the composite metal blank, extrudingthe billet metal ofthe composite blank to areducedweiland anat shoulderextending outwardlyy from the end or the side wall, seating a fiat-facedring of corrosion-resistant metal around the pilot portion of saidshoulder in intimate contact with the pilot portion and shoulder,forming iiush fiatv end faces on the pilot portion and ring, coveringthe rin! and pilot portion with a corrosionresistant disk having aiiatend face, placing the end face of the disk in full intimate contact withthe flush iiat end races oi' the pilot portion and ring, and welding thebillet, ring and disk togetherunder pressure to produce a compositeblank having a main body portion composed ot diameter size. terminatingthe extrusion -operl ation in advance of the disk metal; piercing thereduced-diameter` portion of the extruded blank .to i'orm s, cup fromthe billet metal, and forging the resulting pierced blank to formthereon an elongated hollow stem withl an outvtrardly.l flaring headportion covered with corrosionresistant metal from the disk and havinga. peripheral rim covered with corrosion-resistant metal from the ring.

4. In the method of making POPD'et valves having corrosion-resistantmetal clad heads and seating faces, the steps whichcomprlse forming ametal billet with a reduced-diameter end pilot portion having anVupstanding cylindrical side billet metal clad at one end with a skirtedcover composed or the disk andvring metals.

- JOHN WIBCHHUBEN.'

"nnrsnnncns crrnn The following references are oi record in the ille 'cithis patent: l

v UNITED STATES PATENTS Number V om: Britain nos

